The Experimental Observation of Replica Symmetry Breaking in Random Lasers

Spin-glass theory is one of the leading paradigms of complex physics and describes condensed matter, neural networks and biological systems, ultracold atoms, random photonics, and many other research fields. According to this theory, identical systems under identical conditions may reach different states and provide different values for observable quantities. This effect is known as Replica Symmetry Breaking and is theoretically revealed by the change in shape of the probability distribution function of an order parameter named the Parisi overlap.

Despite the profound implications in the new physics of complexity, a direct experimental evidence of the Replica Symmetry Breaking transition, in any field of research was never reported.

C. Conti and coworkers show that pulse-to-pulse fluctuations in random lasers, and  a direct measurement of the Parisi overlap, unveil a transition to a glassy light phase in random lasers compatible with a Replica Symmetry Breaking.

This is the first evidence of Replica Symmetry Breaking and the first direct measurement of the Parisi overlap.

Reference:

N. Ghofraniha, I. Viola, F. Di Maria, G. Barbarella, G. Gigli, L. Leuzzi and C. Conti reported on the first evidence of Replica Symmetry Breaking in Random Lasers by the direct measurement of the Parisi overlap distribution function (arXiv:1407.5428, Nature Communications 2015)

 

Designing Beauty: The Art of Cellular Automata

A new book on the Game of Life, and specifically on the Art of the Game of Life has been published by Springer. Edited by A. Adamatzky and Genaro J. Martinez, the book is part of the Series on Emergence, Complexity and Computation with artistic representations from simple mathematical models at the edge of physics and biology. The book contains a chapter by C. Conti on the Enlightened Game of Life.

 

Glauber oscillator and time travel

The standard quantum mechanics does not forbid time-travel. However, some alternative formulations (based on the so called “rigged Hilbert space”) include irreversibility as a fundamental principle: a quantum particle that decays cannot travel back in time.

There are not direct evidences of the irreversibility of decay processes, but the new quantum mechanics predicts that the decay rates are quantized.

If one observes the quantization of the decay rates, one can claim to have provided experimental support to the irreversible formulation of quantum mechanics.

In simple terms, one can claim that time-travel is not possible at the quantum level (…and also at the classical level).

Silvia Gentilini, Maria Chiara Braidotti, Giulia Marcucci, Eugenio Del Re, and Claudio Conti simulated in the laboratory one of the simplest models of the irreversible quantum mechanics, that follows an original proposal of Glauber. A laser beam emulates a quantum particle in a reversed harmonic oscillator, as a result the first experimental evidence of the quantization of decay time is reported in a paper published in Scientific Reports.

(reprint from the former complexlight.org website)

Time Travel is NOT Possible (press release)

Time travel is not possible*

Press release on the Templeton project, Generalized Uncertainty Principle and The Photon (2015-2018)

Our paper on the Glauber oscillator and Time Travel had a relevant impact in the press …

http://www.repubblica.it/scienze/2015/11/06/news/ritorno_al_futuro_rassegnamoci_i_viaggi_nel_tempo_sono_impossibili-126767806/

http://www.ansa.it/scienza/notizie/rubriche/fisica/2015/11/06/ritorno-al-futuro-i-viaggi-nel-tempo-sono-impossibili_70ced271-9136-4996-ac6b-44d0ac732da0.html

http://www.media.inaf.it/2015/11/06/viaggi-nel-tempo-indietro-non-si-torna/

http://m.vanityfair.it/news/italia/15/11/07/scienza-dice-non-si-torna-indietro-nel-tempo

Comprehensive press release pdf files:

Rassegna stampa_cs_viaggi nel tempo (pdf 1)

Rassegna stampa_cs_viaggi nel tempo (pdf 2)

*maybe, if you are subnuclear particle in proximity of a supermassive black hole you may have some chances to go back in time for a femtosecond